Combination metering pump and fuel spray valve



Oct. 14, 1924. 151 4 4 H. B. PETERSON COMBINATION METERING PUMP AND FUELSPRAY VALVE Filed Oct. 25 1922 IN VEN TOR.

HO WARD a PETfP-SO/M Patented Oct. 14, 1924.-

UNITED STATES- HOWARD IB. PETERSON, or SAN FRANCISCO, CALIFORNIA.

COMBINATION METERING PUMP AND FUEL SPRAY VALVE.

Application filed October 25, 1922. Serial No. 596,708.

To all whom it may concern: 1

Be it known that I, HOWARD B. PETERSON, a citizen of the United States,residing at the city and county of San Francisco and State ofCalifornia, have invented new and useful Improvements in a CombinationMetering Pump and Fuel Spray Valve, of which the following is aspecification.

This invention relates to a Diesel type of internal combustion engine,and especially to a combination metering pump and fuel spray valve,which is particularly adapted for small horse-power units where solidinjection is employed.

The object of the present invention is to generally improve and simplifydevices of the character described; to provide a combined metering pumpand fuel spray valve, which may be constructed as a single compact unitand directl attached to the cylinder head of an engine; to provide meansfor advancing or retarding the time of injection, and simultaneouslyincreasing or decreasing the quantity of fuel injected; to provide ametering pump which also serves the function of a fuel or injector pump,and which is designed to receive oil from the fuel feed line undercomparatively low pressure and inject at high pressure; to eliminatesevere duty on the-pump stufling box by subjecting it to the lowpressure of the feed line only; to provide a structure which permitsby-passing and return of all leakage oil from the pump and fuel sprayvalve to the low pressure feed line; and further to automaticallyactuate the fuel spray valve in conjunction with the fuel pump andwithout resorting to the use of exterior actuating mechanism, stuflingboxes, etc. Other objects will hereinafter appear.

One form which my invention'may assume is exemplified in the followingdescri tion and illustrated in the accompanying rawings, in which Fig. 1is a side elevation in section showing the combined metering pump, andfuel spray valve, said view also illustrating the mechanism whereby areciprocal movement is imparted to the pump plunger and whereby thestroke is increased or decreased, and the time of the stroke advanced orretarded.

Fig. 2 is a cross section on line 22,

fieferring to the drawings in detail, A indicates the cylinder head of aDiesel type of engine, B the cam shaft, and C the combined metering pumpand fuel spray valve. The metering pump and fuel spray valve consists ofa casing 2, which is secured to the cylinder head in any suitable manneror as here shown by a screw collar 3. Formed in the casing 2 is acentral cylinder chamber 4, and slidably mounted therein is a seat is aspring 8 and a removable plug 9.

Formed on'the lower end of the pump cylinder is a fuel valve 10. Thisvalve is of the needle valve type and is arranged to normally engage aseat 11 formed at the upper end of a fuel spray orifice or nozzle 12.The fuel or needle valve indicated at 10 is reduced in diameter whencomparison is made with the pump cylinder 5, and an annular chamber 13is therefore formed in the lower end of the main cylinder which with thefuel delivering passage 6 communicates. Reciprocally mounted in the pumpcylinder is a plunger 14, and forming communication between the pumpcylinder and the annular chamber 13 is one or more passages such asindicated at 15. The plunger 14 extends upwardly through the maincylinder chamber 4 and passes out through a stuffing box generallyindicated at 16. The upper end of the pump plunger is headed as at 17and a spring is interposed between the head and the upper end of thestufiing box as at 18. The pump cylinder 5 divides the main cylinderinto two chambers, to-wit, the lower annular chamber 13 and an upperchamber 19. This chamber is in constant communication with the fueldelivery line through a port indicated by dotted lines at 20. Thechamber serves two functions, first that of a by-pass chamber throughwhich any leakage oil escaping from the plunger 14 or the fuel valve 10may be returned to the fuel line, and secondly that of a housing andguide for a spring 21, which is interposed 7 between the upper end oftheffiplump cylinder also serves a second function, to-wit, that ofdetermining the final pressure under which the oil is injected into thecylinder, as will hereinafter be described.

To reduce leakage through the stufiing box 16 to a minimum, it'will bestated that it is only subjected to the fuel line pressure and in factis not at all times even subjected to this pressure as a seat is formedon the lower end of the head 22, as indicated at 23, which is engaged bya valve member 24 formed on the pump plunger. This seat prevents leakagewhen the pump plunger assumes its raised position and it can thereforebe seen that the stuffing box is only subjected to pressure whentheplunger is 'depressed, and as the line pressure is comparatively low,severe duty as far as the stufling box is concerned is practicallyeliminated.

The plunger shown in the present instance serves two functions, firstthat of a metering pump, and secondly that of an injector. It istherefore necessary that means be employed for imparting a reciprocalmovement to the plunger, and also that means be provided for increasingor decreasing the stroke, and also for advancing or retarding the timeof the stroke. This is accomplished in the present instance as follows:Secured on the cam shaft B is a cam 25. Turnably mounted on the .camshaft is a bell crank 26. Journaled in the upper arm of the bell crankis a roller 27 through which reciprocal movement is imparted to a roller28 and a tappet 29, and extending through the lower arm of the bellcrank is a shaft 30, on which is secured a governing eccentric 31. Theshaft, together with the eccentric, may be manually turned or actuatedby a governor. Any rotary movement imparted will, of course, transmit arocking movement to the bell crank and this movement will not onlyincrease or decrease the stroke of the tappet, but it will also advanceor retard the time of the stroke. The movement of the tappet may betransmitted to the pump plunger 14 in any suitable manner, or as hereshown by an interposed rocker arm 32. If the engine is operating under afull load, the bell crank, together with the roller 27 and the eccentric31, will assume the position shown in Fig. 1, but if a reduced load isdesired, rocking movement will be imparted to the bell crank in thedirection of arrow a. Roller 27 will in that instance move away from thecenter line drawnthrough the cam shaft and tappet, as indicated at 3333,and as such will not only decrease the stroke of the tappet as it movesaway from the same, but it will also retard the time of the stroke, asthe cam will engage the roller 27 later than when it assumes the fullline position shown in Fig. 1. In this manner it is possible tosimultaneously increase or decrease the stroke of the plunger 14 as itis actuated by the tappet through-means of the rocker arm, and it issimilarly possible to advance or retard the time of injection.

The present device is particularly adapted for automobiles,.trucks,tractors, marine engines, etc., employing comparatively smallhorse-power engines, but may of course be employed in larger units ifdesired. The entire mechanism employed is exceedingly simple and thestructure is so compact that it may be directly attached to the cylinderhead of practically any standard make of high pressure internalcombustion engine.

The advantages of the structure are manifold and will hereinafter bereferred to. A brief description of its operation will, however, berendered so that the advantages obtained will be appreciated,

In operation we will assume that the fuel line pressure is 1000 poundsand that it is desired to inject the oil into the cylinder un der apressure of 4000 pounds. In that instance it can readily be seen that apressure of 1000 pounds will be exerted in the chambers 19 and 13 of themain cylinder and that the pump cylinder will be balanced as thepressure on each end will be equalized. This is due to the fact thatchamber 19 is in communication with the fuel line through the by-pass 20and that chamber 13 is in communication with the fuel line through thpassage 6. During the upstroke of the plunger 14, oil will pass thecheck valve 7 and enter chamber 13 through passage 6, and it will alsoenter the chamber of the pump'cylinder 5. During reverse movement of theplunger, the check valve seats and prevents return movement through thepassage 6 and as this is the case, the pressure will increase in chamber13 until thetension of the spring 21 is overcome.

rection, and as the fuel valve is directly connected therewith, it willlift from the seat and will permit the oil to discharge through theorifice 12. The moment reverse movement' is imparted to the .plunger 14,the pressure will instantly ceas and pressures in the respectivechambers will again balance, thus permitting the spring 21 to return thepump cylinder to normal position and the valve 10 to engage the seat.This particular The pump cylinder 5 will then move in an upward di-'movement of the fuel valve and pump cylinder, in conjunction with theplunger, is important as it eliminates the use of exterior mechanism forraising or lowering the fuel valve. In other words it might be statedthat the fuel valve is hydraulically actuated and that this hydraulicoperation is dependcut on the movement of th pump plunger. Thisstructure is of further importance as any leakage which may take placebetween the pump cylinder and the plunger will enter th upper cylinderchamber, and similarly any leakage which may escape from the chamber 13and upwardly around the pump cylinderr5; this leakage of oil beingreturned to the fuel line through the bypassage 20. The stufiing box isat no time subjected to th high pressure created in the pump cylinder orin the annular chamber 13 as fuel line pressure is always maintained inthe upper end of the cylinder. To prevent surging in the fuel line orthrough the by-pass 20, a pair of air pockets 38 is formed in the lowerend of the head member 22. These pockets form 'air cushions for the bodyof oil maintained-in the upper end of the cylinder and this air willcompress when upward movement is imparted to the c linder 5 duringdownward movement 0 the plunger 14. The upward movement of the cylinder5 is, however, very slight as the pressure in chamber 13 is high andtherefore rapidly relieves itself when valve 10 unseats. In actualpractice themovement of the valve and the cylinder 5 will probably notexceed 2 or 3/1000 of an inch. Any

tendency to produce a surge in the fuel line is therefore very small,but even this is revented by providing the cushioning cham- The tensionof the spring 21 may be increased so that the injecting pressure may beraised as desired, this being accomplished by inserting larger springs,and conversely smaller springs if it is desired to reduce the injectingpressure. The spring 18 could in many cases be eliminated as thepressure in the upper end of the cylinder is in most cases sufficient toreturn the I lunger -14 to its upper normal 'tion. he spring 17 maytherefore be a owtension spring as its duty is merel that of anauxiliary employed to return t e ump lunger.

By the use 0 the present design and structure, a definite amount of fuelis injected to the cylinders. This amount may be varied to suit increaseor decrease in loads, and the-time of injection me also be advanced orretarded as desired. he fuel valve is lifted from its seat without anyex ternal means other than that-which operates the meterin or injectingplunger. Leakage past the p unger and pump cylinder is returned to thefeed line and as such is not lost. Comparatively low pressures may becarried in the fuel line, thereby reducin load and wvere strains in fuelpump and connected mechanism, and similarly relieving the stufiing glandof severe duty. The Y structure permits absolute control of the fuelspray entering the cylinder, and it also controls the quantity injected,the time of inj ection, and the pressure of injection. With' thatmicroscopic lifts generally employed when governing the fuel valve areentirely eliminated as the lift of the fuel valve is in this instancehydraulically actuated during the movement of the plunger.

While certain features of the present in vention are more or lessspecifically illustrated, I wish it understood that various changes inform and proportion may be resorted to within the scope of the appendedclaims, similarly that the materials and finish of the several partsemployed'may be such as the experience and judgment of the manufacturermay dictate or various use ma demand.

aving thus described my invention, what I claim and desire to secure byLetters Patent is-' 1. A device of the character described comprisin acasing having a cylinder chamber formed therein, and a spray orifice inits lower end, a passage formed in the cylinder for delivering liquidfuel under pressure to the cylinder, a check valve in said passage, apump cylinder slidably mounted in the cylinder and having a needle valveon its lower end engaging the spray orifice, a combined metering andinjecting plunger reciprocally mounted in the pump cylinder, means forimparting a reciprocal stroke to the plunger, and means for increasingor decreasing the stroke of the plunger and simultaneously advancing orretarding the time of the stroke.

2. A device of the character described I chamber under pressure,passages formed in 1 the pump cylinder connecting the annular chamberand the pump cylinder chamber, and a plunger reciprocally mounted in thepump cylinder.

3. A device of the character described mounted in the pump cylinder,means comprising a casing having a cylinder chamber formed therein and aspray orifice in its lower end, a pump cylinder slidably mounted in thecylinder, a fuel valve of reduced diameter carried by the pump cylinderand normally engaging a seat in the spray orifice, said fuel valveforming an annular fuel receiving chamber in the cylinder incommunication with the spray orifice, means for delivering a liquid fuelto said annular chamber under pressure, passages formed in the pumpcylinder connecting "the annular chamber and the pump cylinder chamber,a combined metering and injecting plunger or imparting a reciprocalmovement thereto, and means for increasing or decreasing the stroke ofthe plunger and simultaneously advancing or retarding the time of thestroke. i

4. A device of the character described comprising a casing having a'cylinder chamber formed therein and a spray orifice at the lower end ofthe cylinder, a pump cylinder slidably mounted in the cylinder anddividing the cylinder into an upper and a lower chamber,a fuel valvecarried by the pump cylinder and engageable with the seat in the sprayorifice, means for delivering a liquid fuel under pressure to the upperand lower ends of the cylinder chamber, a plunger reciprocally mountedin the pump cylinder, means forming communication between the pumpcylinder and the lower cylinder chamber to admit fuel to the pumpcylinder, means for imparting a reciprocal movement to the plunger, anda spring interposed between the upper end of the cylinder and the upperend of the pump cylinder.

5. A device of the character described comprising a casing having acylinder chamber formed therein and a spray orifice at the lower end ofthe cylinder, a pump cylinder slidably mounted in the cylinder anddividing the cylinder into an upper and a lower chamber, a fuel valvecarried by the pump cylinder and engageable with the seat in the sprayorifice, means for delivering a liquid fuel under pressure to the upperand lower ends of the cylinder chamber, a plunger re ciprocally mountedin the pump cylinder,

means forming communication between the.

pump cylinder and the lower cylinder chamber to admit fuel to the pumpcylinder, means for imparting a reciprocal movement to the plunger, ahead member forming a closure for the upper end of the cylinder, astufling box in the head member through which the pump cylinder plungerextends, and a spring in the upper cylinder chamber interposed betweenthe head and the pump cylinder. w

6. A device of the character described comprising a casing having acylinder chamber formed therein and a spray orifice at the lower end ofthe cylinder, a pump cylinder slidably mounted in the cylinder anddividing the cylinder into an upper and a lower chamber, a. fuel valvecarried by the pump cylinder and engageable with the seat in the sprayorifice, means for delivering a liquid fuel under pressure to the upperand lower ends of the cylinder chamber, a plunger reciprocally mountedin the pump cylinder, means forming communication between the pumpcylinder and the lower cylinder chamber to admit fuel to the pumpcylinder, means for imparting a reciprocal movement to the plunger, ahead member forming a closure for the upper end of the cylinder astuffing box in the head member through which the pump cylinder plungerextends, a spring in the upper cylinder chamber interposed between thehead and the pump cylinder, a valve on the pump plunger, and a seatformed in the head below the stufling box with which said valve isadapted to engage.

7 device of the character described comprising a casing having acylinder chamber formed therein and a spray orifice at the lower end ofthe cylinder, a pump cylinder slidably mounted in the cylinder anddividing the cylinder into an upper and a lower chamber, a fuel valvecarried by the pump cylinder and engageable with the seat in the sprayorifice, means for delivering a liquid fuel under pressure to the upperand lower ends of the cylinder chamber, a plunger reciprocally mountedin the pump cylinder, means forming communication between the-pumpcylinder and the lower cylinder chamber to admit fuel to the pumpcylinder, means forimparting a reciprocal movement to the plunger, ahead member forming a closure for the upper end of the cylinder, astufiing box in the head member through which the pump cylinder plungerextends, a spring in the upper cylinder chamber interposed between thehead and the pump cylinder, a valve on the pump plunger, a seat formedin the head below the stuffing box with which said valve is adapted toengage, and air cushioning pockets formed in the cylinder head in com-IIOnunication with the upper cylinder cham- 8. In a device of thecharacter described the combination with the main cylinder and astationary spray orifice formed in the lower end thereof, of a pumpcylinder slidably mounted in the main cylinder, a fuel valve carried bythe pump cylinder and engageable with a seat in the spray orifice, aspring engaging the pump cylinder and normally maintaining the fuelvalve on its seat, and means for hydraulically raising the fuel valvefrom its seat.

9. In a device of the character described a stationary spray orificeformed in the seat, a pump plunger reciprocally mounted lower endthereof, of a pump cylinder slidin the pump cylinder and extendingthrough ably mounted in the main cylinder, a fuel the main cylinder, andmeans for imparting 10 valve carried by the pump cylinder and movementfrom the pump plunger toraise 5 engageable with a seat in the sprayorifice, the fuel valve from its seat;

I a spring engaging the pump cylinder and normally maintaining the fuelvalve on'its A HOWARD B. PETERSON.

